The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs over the data-link layer (Layer 2) on all Cisco-manufactured devices (routers, bridges, access servers, and switches). CDP allows network management applications to automatically discover and learn about other Cisco devices that are connected to the network.
To permit the discovery of non-Cisco devices, the switch also supports the
Link Layer Discovery Protocol (LLDP)
, a vendor-neutral device discovery protocol that is defined in the IEEE 802.1ab standard. LLDP allows network devices to advertise information about themselves to other devices on the network. This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.
LLDP is a one-way protocol that transmits information about the capabilities and current status of a device and its interfaces. LLDP devices use the protocol to solicit information only from other LLDP devices. Cisco DCNM can use LLDP to discover only servers that are connected to your device.
Note For information on device discovery and manually binding devices to a server, see the Cisco DCNM Fundamentals Guide, Release 5.x.
The LLDP feature supports stateless and stateful restarts.After a reboot or supervisor switchover, the running configuration is applied.
Licensing Requirements for LLDP
The following table shows the licensing requirements for this feature:
LLDP requires no license. Any feature not included in a license package is bundled with Cisco DCNM and is provided at no extra charge to you. For a complete explanation of the Cisco DCNM licensing scheme, see the
Cisco DCNM Installation and Licensing Guide, Release 5.x
LLDP requires no license. Any feature not included in a license package is bundled with the Cisco NX-OS system images and is provided at no extra charge to you. For an explanation of the Cisco NX-OS licensing scheme for your platform, see the licensing guide for your platform.
The LLDP feature has the following prerequisite (for a full list of feature-specific prerequisites, see the platform-specific documentation):
System-message logging levels for the LLDP feature must meet or exceed Cisco DCNM requirements. During device discovery, Cisco DCNM detects inadequate logging levels and raises them to the minimum requirements. Cisco Nexus 7000 Series switches that run Cisco NX-OS Release 4.0 are an exception. For Cisco NX-OS Release 4.0, prior to device discovery, use the command-line interface to configure logging levels to meet or exceed Cisco DCNM requirements. For more information, see the
Cisco DCNM Fundamentals Guide, Release 5.x
Guidelines and Limitations for LLDP
LLDP has the following configuration guidelines and limitations (for a full list of feature-specific guidelines and limitations, see the platform-specific documentation):
LLDP timers and type, length, and value (TLV) descriptions cannot be configured using Cisco DCNM.
The following platform supports this feature. For platform-specific information, including guidelines and limitations, system defaults, and configuration limits, see the corresponding documentation.
You can enable or disable LLDP globally on Cisco Nexus 7000 Series switches.
Note LLDP is enabled globally on Cisco Nexus 5000 Series switches and cannot be disabled.
BEFORE YOU BEGIN
Make sure that you are in the correct VDC.
Step 1 From the Feature Selector pane, choose
Interfaces > Physical > Ethernet
. The available devices appear in the Summary pane.
Step 2 From the Summary pane, click the device on which you want to enable or disable LLDP.
Step 3 Do one of the following:
To enable LLDP on the device, from the menu bar, choose
Enable LLDP Service
To disable LLDP on the device, from the menu bar, choose
Disable LLDP Service
Step 4 From the menu bar, choose
to apply your changes to the device.
Enabling or Disabling LLDP on an Interface
After you globally enable LLDP, it is enabled on all supported interfaces by default. However, you can enable or disable LLDP on individual interfaces or selectively configure an interface to only send or only receive LLDP packets.
Note If the interface is configured as a tunnel port, LLDP is disabled automatically.
Note Beginning with Cisco DCNM Release 5.1, you can enable or disable LLDP on individual interfaces on Cisco Nexus 5000 Series switches.